Editor's Note: This story was updated on Wed., Sept.18 at 11:30 a.m.

A National Grid crew working in the street at Dorchester Avenue at Ashmont Street struck a Boston Water and Sewer Commission main around 6 p.m. on Tuesday, turning Peabody Square into an impassible lake and forcing firefighters to evacuate at least one building after they started smelling a strong odor of gas.

National Grid workers apparently drilled into the main as they were searching for the source of a natural-gas odor that had been wafting through the area since at least Sunday.

By the time BWSC workers arrived on scene shortly after 6:30 p.m. to stanch the flow of water, the flooding had left a 9-foot-by-9-foot flooded hole in the middle of the square.

Police shut Dorchester Avenue through the square, along with streets feeding into it, such as Bushnell Street at Lombard Street. State Police were asked to shut Dorchester Avenue at Gallivan Boulevard.

The flooding did not reach the nearby Ashmont Red Line stop, but it did cause delays on the Ashmont branch. Shuttle buses replaced trains between JFK-UMass and Ashmont until the end of service on Tuesday and for a few hours on Wednesday morning, but T officials said train service was restored around 7:30 a.m. on Wednesday, with delays expected.

On Wednesday morning, work was still ongoing to repair the broken pipe, but water service—which had been interrupted to many homes in the immediate area— was restored. However, some residents and businesses would likely notice discolored water, a common occurrence after a water main break like this one, according to Joe Bailey, a spokesman for BWSC.

"It's safe to consume, but people should use their own discretion. We advise people to let the cold water run periodically and eventually it will dissipate," said Bagley, who advised: "It's not good for washing clothes."

"Right now, crews are still in the process of repairing the main pipe. There's one more exercise needed to insert a type of concrete block to secure the pipe."

Bagley said that the trench on Ashmont Street will remain open after the BWSC repairs are made so that National Grid crews can come back in to fix a gas line.

Boston firefighters, National Grid workers await the arrival of BWSC crews to stop the flooding:

The calm after the torrent stopped: